The present invention is directed to new and useful improvements in filters and in particular to rotary drum vacuum filters.
Rotary drum vacuum filters are well known and utilize filtration members which comprise a cylindrical drum mounted for rotation in a tank containing a slurry solution. Filter media is provided about the outer surface of the drum and a vacuum is applied to the surface of the drum during a period of the filtration cycle as the drum is rotated through the slurry to draw filtrate into filtration compartments within the drum while forming a filter cake on the surface of the filter media. A suitable valve assembly is provided to interrupt the vacuum during a final period of the filtration cycle after the cake bearing portion is clear of the tank and the cake dried. The filter cake is then removed from the filter media by suitable doctoring means. Supply of the vacuum is controlled by the valve assembly which is usually located concentrically with the center of the drum at end trunnions and through which valve assembly the filtrate is conducted outwardly of the filter.
In conventional filters of this type various structures have been utilized for providing the main drum portion of the filter. In general these known structures comprise relatively complex arrangements which require excessive internal filtrate piping systems and drum supporting structures which results in increased cost both in labor and material in assembly and operation of the filter.
It is an object of the present invention to provide an improved drum construction for a rotary drum vacuum filter.
Another object is to provide a novel drum construction which includes means for rapid flow of the filtrate from the filtrate compartment.
It is a further object to provide a drum structure comprised of a minimum number of parts which reduces manufacturing costs and assembly procedures.